Did my doctor fail to diagnose diabetes?

Patient: Hello, I am a 19 year old female with diabetes concerns. In September 2010, I experienced tingling in my fingertips that lasted for nearly two days. A few weeks later, I went to the emergency room and had a CT scan of my chest as well as a chest x-ray and both were normal. However, my blood sugar at the time was 219 mg per deciliter. A week later I had a fasting glucose test that was at about 70, so my doctor “ruled out” diabetes. However, my tingling problems persisted and my doctor referred me to a neurologist. I had an MRI of my brain and cervical spine to test for MS, and both scans were normal. A few weeks ago, on suspicions that my blood sugar was still high, I purchased a home glucose meter (no coding required). When I first tested, my reading was at about 90 two hours after eating, so I thought I had nothing to worry about. However, two weeks later I tested again after dinner and my reading was at 234, followed by 140 when I woke up. I told my doctor and he tested my urine and blood, and both were normal. However, on that day I had intentionally avoided eating sugar and carbs. My doctor seems convinced that I have nothing to worry about, but I have continued to test with the meter I bought and it is consistently high (above 150 two hours after eating) and usually above 120 in the morning. He says that my meter must be faulty even though I have tested it with the control amount repeatedly. Should I be concerned that I have diabetes? Also, I forgot to mention I am 5 feet four inches and 113 pounds. I have never been overweight. Thank you!